Two-Dimensional Spectral Interferometry using the Carrier-Envelope Phase

Two- and multi-dimensional spectroscopy is used in physics and chemistry to obtain structural and dynamical information that would otherwise be invisible by the projection into a one-dimensional data set such as a single emission or absorption spectrum. Here, we introduce a qualitatively new two-dimensional spectroscopy method by employing the carrier-envelope phase (CEP). Instead of measuring spectral vs. spectral information, the combined application of spectral interferometry and CEP control allows the measurement of otherwise inseparable temporal events on an attosecond time scale. As a specific example, we apply this general method to the case of attosecond pulse train generation, where it allows to separate contributions of three different sub-cycle electron quantum paths within one and the same laser pulse, resulting in a better physical understanding and quantification of the transition region between cutoff and plateau harmonics. The CEP-dependent separation in time between two full-cycle spaced attosecond pulses was determined to modulate by (54 +/- 16) attoseconds

Germline mutations in the oncogene EZH2 cause Weaver syndrome and increased human height.

The biological processes controlling human growth are diverse, complex and poorly understood. Genetic factors are important and human height has been shown to be a highly polygenic trait to which common and rare genetic variation contributes. Weaver syndrome is a human overgrowth condition characterised by tall stature, dysmorphic facial features, learning disability and variable additional features. We performed exome sequencing in four individuals with Weaver syndrome, identifying a mutation in the histone methyltransferase, EZH2, in each case. Sequencing of EZH2 in additional individuals with overgrowth identified a further 15 mutations. The EZH2 mutation spectrum in Weaver syndrome shows considerable overlap with the inactivating somatic EZH2 mutations recently reported in myeloid malignancies. Our data establish EZH2 mutations as the cause of Weaver syndrome and provide further links between histone modifications and regulation of human growth

A Model of Vertical Oligopolistic Competition

This paper develops a model of successive oligopolies with endogenous market entry, allowing for varying degrees of product differentiation and entry costs in both markets. Our analysis shows that the downstream conditions dominate the overall profitability of the two-tier structure while the upstream conditions mainly affect the distribution of profits. We compare the welfare effects of upstream versus downstream deregulation policies and show that the impact of deregulation may be overvalued when ignoring feedback effects from the other market. Furthermore, we analyze how different forms of vertical restraints influence the endogenous market structure and show when they are welfare enhancing

Specific staining of human chromosomes in Chinese hamster x man hybrid cell lines demonstrates interphase chromosome territories

In spite of Carl Rabl's (1885) and Theodor Boveri's (1909) early hypothesis that chromosomes occupy discrete territories or domains within the interphase nucleus, evidence in favor pf this hypothesis has been limited and indirect so far in higher plants and animals. The alternative possibility that the chromatin fiber of single chromosomes might be extended throughout the major part of even the whole interphase nucleus has been considered for many years. In the latter case, chromosomes would only exist as discrete chromatin bodies during mitosis but not during interphase. Both possibilities are compatible with Boveri's well established paradigm of chromosome individuality. Here we show that an active human X chromosome contained as the only human chromosome in a Chinese hamster x man hybrid cell line can be visualized both in metaphse plates and in interphase nuclei after in situ hybridization with either 3H- or biotin-labeled human genomic DNA. We demonstrate that this chromosome is organized as a distinct chromatin body throughout interphase. In addition, evidence for the territorial organization of human chromosomes is also presented for another hybrid cell line containing several autosomes and the human X chromosome. These findings are discussed in the context of our present knowledge of the organization and topography of interphase chromosomes. General applications of a strategy aimed at specific staining of individual chromosomes in experimental and clinical cytogenetics are briefly considered

The possible existence of Hs in nature from a geochemical point of view

A hypothesis of the existence of a long-lived isotope 271Hs in natural molybdenites and osmirides is considered from a geochemical point of view. It is shown that the presence of Hs in these minerals can be explained only by making an additional ad hoc assumption on the existence of an isobaric pair of 271Bh-271Hs. This assumption could be tested by mass-spectrometric measurements of U, Pb, Kr, Xe, and Zr isotopic shifts.Comment: 5 pages, no figures. Physics of Particles and Nuclei Letters, 2006, Vol. 3, No. 3, pp. 165-168 in pres

Multiple phases of human occupation in Southeast Arabia between 210,000 and 120,000 years ago

Changing climatic conditions are thought to be a major control of human presence in Arabia during the Paleolithic. Whilst the Pleistocene archaeological record shows that periods of increased monsoon rainfall attracted human occupation and led to increased population densities, the impact of arid conditions on human populations in Arabia remains largely speculative. Here, we present data from Jebel Faya in Southeast (SE) Arabia, which document four periods of human occupation between c. 210,000 and 120,000 years ago. The Jebel Faya record indicates that human occupation of SE Arabia was more regular and not exclusively linked to major humid periods. Our data show that brief phases of increased rainfall additionally enabled human settlement in the Faya region. These results imply that the mosaic environments in SE Arabia have likely formed a population refugia at the end of the Middle and the beginning of the Late PleistoceneOpen Access funding enabled and organized by Projekt DEAL.https://www.nature.com/srepBiochemistryGeneticsMicrobiology and Plant Patholog

Characterization and Tuning of Ultra High Gradient Permanent Magnet Quadrupoles

The application of quadrupole-devices with high field gradients and small apertures requires precise control over higher order multipole field components. We present a new scheme for performance control and tuning, which allows the illumination of most of the quadrupole-device aperture because of the reduction of higher order field components. Consequently, the size of the aperture can be minimized to match the beam size achieving field gradients of up to 500 T/m at good imaging quality. The characterization method based on a Hall probe measurement and a Fourier analysis was confirmed using the high quality electron beam at the Mainz Microtron MAMI